Avatar Hearts: Open the Door
by Agent S7
Summary: AU Book 3. The gAang has faced hardships before, but none compare to the darkness about to be unleashed upon the world...Kingdom Hearts Crossover. KA, Tokka. Doesn't require knowledge of KH.
1. Part I: The Door

Author's Note: Don't be scared of the fact that this is a Kingdom Hearts crossover--I've tried to make this story as readable to my fellow Avatards as possible...and if you don't like it, then you get a cookie. But if you keep reading and replying to this fanfic then you'll get not one, not two but THREE cookies. I'm sure you can do the math.--s7

Avatar Hearts

PART I:

The Door

Chapter 1

Aang's eyes moved from cloud to cloud in the sky, to the setting sun and then slowly fell on Katara, sitting next to her on the large hill overlooking Ba Sing Se. "I've been having these weird thoughts lately."

"Really? Like what?" asked Katara.

"Like…" Aang struggled with his words. "…is any of this for real or not?"

Katara grinned. "Of course this isn't real, Aang. You were shot in the back with a bolt of lightning!"

"I…was?" Aang paused, trying to remember. "I was. Wasn't I?"

"Yes. You died, too. It was only for a few minutes but it did the trick. Death's a bit angry that you, well, that you lived. So you're going to be stuck here for a while. But that suits my needs perfectly well."

"You're not Katara, are you? You're some sort of spirit…"

"It all depends on your viewpoint, really. I may be Katara, I may be a spirit. I may be something more. You'll have to decide this for yourself. The real point here is that your heart holds a special bond with me—with Katara—, one that will be extremely important in the coming events."

"I don't understand."

"People seldom do. I don't really understand it myself, and it's all _about_ me."

"Who _are_ you?"

"Aang." Katara turned to the Avatar, her face showing an expression of concern. "Aang, the Heartless are _coming_. And when they come you'll need to be ready."

The horizon dripped downward into nothing. "I'm going back to sleep again, aren't I? I mean, I won't be able to talk to you."

"I'll always be with you, Aang. So will Sokka and Toph. In heart, body and spirit we all share unbreakable bonds. Remember that."

Katara's face vanished, leaving Aang once again precariously close to Death's icy domain.

--

"How's Aang?"

Katara jumped, startled. She hadn't seen Sokka and Toph walk up behind her, probably because of her mindset. Her mind focused entirely on her wounded friend. Nevertheless, her answer was quick. "Not good, Sokka. I mean, _good_, but he's still asleep."

"Two weeks now," said Toph. "He's been out for two weeks." The earthbender shook her head worriedly.

"He's _going_ to wake up, Toph," said Katara.

"But _when_?" Sokka shot back. "I know Aang's our best—our _only_—shot at taking the Fire Nation, but If he doesn't wake up soon Sozin's Comet will come and then…" He stopped.

"We'll die," Toph said, glaring at Sokka. "Admit it. Don't just pretend it's some little crazy idea floating around in the air—it could happen. It _might_ happen."

"No, it _won't_," Sokka growled. "Aang's going to week up, alright? So shut up right now or I'll--"

"_Quit it. Both of you. Now._" Katara's words were so forceful, so packed with rage, that the two others immediately turned to her and shut their mouths. "Aang has never, _ever_ let us down. He's saved our sorry butts more than any of us can count. He's coming back, okay?" Toph raised her hand as if to reply, thought better of it and stormed off.

"I'm going to bed, Sugar Queen. G'night." Toph skulked away without looking back.

Sokka broke the silence first. "Katara…what are we going to do?"

"I don't know," said Katara. "Somebody needs to talk to Toph. She's been weird lately…"

"I think she just feels hopeless. We _all_ feel a little hopeless right now."

"Then cheer her up."

Sokka studied Katara's face. "What are you talking about?"

"Sokka, she _likes_ you. Can't you tell?"

"She likes all of us."

"No, genius. She _likes_ you."

Silence.

"Um. Um…I'm involved. With Suki. Right?"

Katara shook her head. "Yeah, but she doesn't care. You're the only guy she has a chance with, in her eyes at least."

"I am?"

Katara shook her head. "There's something in the guy brain that prevents you all from understanding things unless girls say them twice. She _thinks_ you're the only guy she has a chance with."

"Is she right?"

"Sokka, you don't just see her like some helpless blind girl and you don't see her like some brainless musclehead either."

"Neither does Aang."

"Yes, but she probably understand that she could never be with the Avatar," said Katara.

Sokka stared at the floor. "I've got to give this some thought. Dad promised to go fishing with me today…I think I will. I hope you feel better, Katara."

"I will," Katara replied. "Wait, what?"

"I know you miss Aang more than any of us."

Katara smiled. "Yeah. I do." Sokka walked out onto the deck of the captured ship, leaving the waterbender alone with her thoughts. She went into Aang's room and looked down over him.

"Aang, I don't know if you can hear me. I don't know where you are or if you'll wake up. But…" she hesitated "…I've been thinking a whole lot about what you said in the South Pole. I keep thinking, you know, that we're…_not_ kids. Not anymore. Not after the things we've seen. But we're not adults either.

"I don't know what I'm trying to…I just…I _miss_ you, Aang. I _do_. And it feels like everything's falling apart, and if you were here maybe things would get _better_. Even a little. We don't even have to fight the Fire Nation, you know? We can…all of us can just live in solitude I guess. I don't know what I'm trying to say. Just please…please wake up, Aang.

"Please."

--

The Dai Li claim to protect the city of Ba Sing Se with their lives. They do not. They claim to Azula to protect her with their lives. They do not. The one thing the Dai Li protect with their own lives is their own lives. Like rats they scamper about and hide, ever searching for the stronger leader to hide behind. And when something enormous, something terrifying comes into being that might just be a threat to their life, they tell their fearless leader all about it.

"Captain Satoshi!" Private Leers stammered, stumbling out of the mine's darkness. "Captain Satoshi!"

The Captain turned his weathered face to Leers. "Leers. Calm yourself. What do you have to say?"

"I found it! No one believed in it anymore but it's _there_, by the spirits, it's _there_!"

"Private," Satoshi said gently. "Private Leers. Come into my office and we will discuss this over a warm cup of tea."

Leers was more than agreeable to this idea. The two sat down by Satoshi's desk and the Captain sipped his green tea while Leers gushed about his experiences, about being lost in the mine, about his unbelievable discovery. Satoshi listened carefully, seemingly uninterested but listening to the words; to the words themselves, their tone and their actual meaning.

After the third telling Leers was calm. The Private thanked the spirits themselves that he could talk so freely with his Captain, gave his blessings and requested another cup of tea. Captain Satoshi obliged, for what else could he do for such a wonderful agent?

The poison was quick-acting—Leers was dead after three sips.


	2. Chapter 2

"I certainly hope this is important, Captain Satoshi."

"Lady Azula," replied the Captain, "I assure you, this is _extremely _important."

Azula narrowed her eyes. "You are one of my most trusted agents, Satoshi. You told me to bring no one else. I did not. I _believe_ this is not a trap. I _believe_ you are loyal. Yet here we are, miles below Ba Sing Se in these disgusting crystal catacombs of yours. I suppose you think a trap would be simple to pull on some adolescent princess?" Azula rose a hand up in the air and it lit with blue fire. The fire princess grinned and it vanished in a puff of smoke. "You, of course, remember what happened to Sergeant Akira when he tried to betray me?"

Satoshi did not flinch. "I do remember very well. He deserved every ounce of pain that he received." He stared into Azula's eyes. "I will not betray you, Azula." It was a challenge—he had called her by her true name.

Azula laughed genuinely. "I like you. Satoshi, is it? You've got guts for an earthbender. Now, what is it you have to show me?"

The two continued through the increasingly dark passageways.

"I'm certain you know that Ba Sing Se is the oldest city in the world?"

"I might. Humor me."

"These are the arcane ruins of Old Ba Sing Se. Thousands, perhaps millions of years old. Now, I know you do not hold much stock in legends, Lady Azula, but there is one I believe you would find _immensely _interesting."

"Do continue."

"There is an old creation myth known to the moldy, venerable scholars of Ba Sing Se University. They seldom speak of it—it is blasphemy. They keep the legend only in the blind hope that it is important. I never bothered with the details during my study of folklore at the University, but I do remember this much.

"The myth states that before either this or the Spirit World existed there was a war in the stars themselves. A ferocious battle between what is good and what is evil."

"You _can't_ still believe in good and evil. I thought you were smarter than that."

"Do you want to hear the legend or not?"

Azula glared at Satoshi dangerously. "Continue."

"After much bloodshed and destruction, a new world was created to seal the Darkness. Guardians were placed upon this new world to prevent it from being released, guardians of the Door to Darkness. Some had been granted power over the elements to better prevent the seal from being broken. One was given a great deal of power—he was the Avatar. Spirits watched over the world, governed the actions of nature.

"Over millennia the guardians, the Avatar and the Spirits themselves forgot their true purpose, and eventually decided that the old story their ancestors had told was nothing more than a ridiculous myth. I agreed with them…until now."

"Wonderfully told," said Azula, yawning. The two had stopped—there was a hole in the ground of the corridor, a ladder leading down into a dark chamber. "Now, will you get to the point?"

"Gladly. Come." Satoshi beckoned, climbing down the ladder. Azula glanced behind her, secretly ashamed that her curiosity had her so enamored. She descended into the pitch black chamber and finally felt her feet touching hard ground. There was a faint glow from behind her, on the far side of the area.

She turned.

The light was blinding. The monolithic ivory door glowed with such power and contrast that Azula had to turn away for a moment to adjust to it. Tall and thin, it was ornate and covered in foreign symbols that looked vaguely like Earth Kingdom kanji. It was a fearsome sight, and Azula felt the overpowering compulsion to fall to her knees, bow and weep for humanity. She forced herself not to, only allowing one tear to drop.

"So," she said, steadying her voice, "according to your myth some great power is sealed within this door?"

"Yes."

Silence. Azula took in the runes and the light, yet something tingled in the back of her mind. There was something more behind the door, something Satoshi was unable or unwilling to see. For a moment the princess saw—or thought she saw—a pool of blackness at her feet, staring with unreal eyes. She stared back for a moment, hypnotized. Then she turned to Satoshi once more.

"How do we open it?"

--

The sun lit up the May sky, the scorching heat a firebender's boon. Zuko had never been happier to feel summer's aura than now and it seemed Mai agreed with him. The pair relaxed in a private bedroom, embracing each other. Occasionally the ship would hit a nasty wave and one would fall off the bed, but they would soon get back together.

"Zuko."

"Mm?"

"Are you really happy?"

Zuko looked into Mai's eyes. Her expression remained unreadable. "Yes."

"You're so pissed off all the time. It's just sort of hard to tell."

The prince immediately got up from the bed. "Oh, really?"

"I'm just telling the truth."

"I'm not angry! I'm ecstatic! I'm going home at last! What would I have to be angry about?"

Mai gazed at Zuko. The prince was now standing up, glaring back at her.

"I'm sorry, Zuko, but it's obvious you're still upset about locking up General Iroh."

"I'm not—I'm not upset!"

"If you're going to try and bottle up your feelings at least do a better job of it."

Zuko laughed bitterly. "I suppose you're an expert at that."

Mai stood up. "What's happened to you, Zuko?"

"I don't know!" said Zuko. "Gee, I guess being scarred and banished for two years will really get to you!"

"It's not about that," Mai replied. "That's a part of it, but that's not all of it."

"I'm going for a walk," growled Zuko. The Fire Prince walked for the door, took one last glance at Mai and stormed off.

--

Aang broke to the surface and climbed out of the icy darkness, coughing desperately. Katara stood next to him, her presence warming him, warding away the bitter taste of oblivion. The Avatar collapsed, again finding himself on the overlook. He stopped for a moment and glanced up at Katara pitifully. "Is this going to happen…often?"

"I told you, Aang. Death is not an easy experience to recover from." The familiar spoke once more, voice, at once Katara's and the voice of ageless.

"Okay," said Aang, trying to relax. "Okay. I…I understand that you want to warn me about something."

"You're being more upfront than last time. Obviously you are closer to you Awakening."

"I'm going to wake up soon?"

"In several ways. Your physical body will awaken, as will your spirit and heart. But, most importantly, you will awaken to your true destiny."

Aang's eyes widened. "What? But I thought my destiny was to defeat the Firelord? I thought I was supposed to bring peace to the Four Nations?"

"It is. It _was_. But things change," said Katara mournfully. "When the darkness rises once more—not the darkness of mortals but the darkness of the World itself—lots of things change." Katara turned to face Aang, her eyes glittering with tears. "Aang, you will lose people dear to you. People that you love. You will lose a part of your family."

Instead of confusion an incomprehensible sadness brewed within Aang. It was not anxiety; it was knowing. "I don't want to. I'm not ready for this."

"Aang, we have little time. Open your hand."

He did so and Katara put her hand in his for a moment. She then pulled it away, leaving a small chain. At the end of it was a small, ornate heart medallion.

"It's the key to a weapon. Whenever you need it hold out the chain and think of me. Think of Katara."

Aang studied the girl's face. It was at once unfamiliar. "Who _are_ you? Which spirit are you?"

"I'm not spirit, nor am I a human. Then again, I _am_ Katara."

"No," Aang said, feeling almost angry. "You're not."

The girl smiled. "I'm afraid we're out of time," she said. "Hold onto your heart tightly—this next one's going to be a doozy."

Tendrils burst from the grounds, shadowy and unclear. They wrapped around Aang's arms, restrained him, and Aang felt himself being pulled under to teeter outside oblivion once more.

--

(Author's Note: Wow, it's been a long time since I've updated! Well, here it is! Chappy deuce! Chapter three will coming soon…hopefully:P)


End file.
